Hollow tubular spirally wound covered metallic anchor



June 4, 1963 H. E. Movn-TIE 3,091,990

HoLLow TUBULAR SPIRALLY woUNn COVERED METALLIC ANCHOR Filed March 24. 1960 38 5P 48 54I20\- l ,.24

A/ mllllmll f1 mjnm m 3,0%,999 Patented June 4, 1963 3,091,990 HOLLOW TUBULAR SPRALLY WOUND COVERED METALLIC ANCHOR Harland E. McVittie, Chicago, Ill. (RG. Box 986, Maitland, Fia.) Filed Mar. 24, 1960, Ser. No. 17,326 4 Claims. (Cl. 85-2.8)

This invention relates to anchors and more particularly to expansion type anchors which may be used in a wide variety of building materials.

There are numerous anchors which are commercially available at the present time. Many anchors are Iof the expansion type, `and they are sold under various trademarks and trade names.

An object of the invention is to provide structural and functional improvements in the expansion type of anchor.

Another object .of the invention is to provide an expansion anchor which may be produced at an exceedingly low unit cost. This has the realistic advantage of making available anchors at a low unit cost so that they may be used in places where there is a temptation to use improvised anchors such as ywooden plugs or in some cases, no anchors at all.

A still further object of the invention -is to provide an expansion type anchor which may be made available in a variety of sizes to suit widely divergent needs. For example, the anchors may be made very small such as would be required for hanging curtain rod brackets on a plaster or plasterboard wall. The various gradations of sizes may be increased to the extent that heavy industrial equipment may be anchored with the aid of large size anchors in accordance with the invention. Yet, the same principles of the invention are preserved throughout the size range of anchors.

Briefly, an anchor in accordance with the invention is made of a group of spirally wound wires covered with a resilient substance such as a resilient plastic or rubber. This is the main body of the anchor. To make the main body functional, means may be supplied at both ends of the spirally wound group of wires to spread the wires both from the front and rear ends thereot` so that an exceedingly firm anchorage is obtained, after which a screw or bolt may be threaded into and removed from the anchor any number of times while the anchor remains firmly in place in an opening .of the wall, floor, etc. within which the anchor is fastened.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of an anchor exemplifying the invention.

FIGURE 2 is a sectional view showing the anchor when it is first placed in an opening.

FIGURE 3 is a sectional view similar to FIGURE 2 but showing the anchor after it has been partially installed.

FIGURE 4 is an enlarged sectional view of the anchor when it is partially fastened in place.

FIGURE 5 is a sectional view showing the anchor fully installed.

FIGURE 6 is a sectional view taken on the line 6 6 of FIGURE 3.

FIGURE 7 is a sectional view showing a modification.

In the accompanying drawings there is an illustration of an anchor 10 which exemplifies the invention. FIG- URES 2-5 disclose an opening -12 in a support or member 14 that diagrammatically represents any material with which an expansion type anchor may be used. As is .tubular core.

custom-ary opening `12 is drilled or otherwise formed in member 14 prior to application of the anchor.

Anchor 10 is clearly shown in FIGURES 4 and 6. It is made of a group 16 of spirally wound wires providing a The wires are metal, Iand it has been found that aluminum wires or wires of an aluminum alloy are ideally suited for anchor 10. The envelope conguration of the group of wires is approximately cylindrical and therefore cover or pocket 18 is also cylindrical. The cover encases the wires and is made of a flexible, resilient substance, for example plastic or rubber. An end cap or wall 20 is adhered to or formed integral with one end of cover 18, and it has a central aperture 22 therein. The opposite end of the cover 118 is open.

Face plate '24 is connected to the otherwise open end of cover y18, for example by being cemented to the cover or welded or otherwise joined to one or more of the wires in the group of spirally wound wires .16. 4By attaching to only `one wire of the group, the others are free to spread in the manner `described subsequently. There is an enlarged -central opening 26 in face plate .24, and a plurality of prongs 28 are struck from the face plate to grip into the material of member Y14. Light hammer blows are all that is necessary to engage the prongs 28 in the member 14, depending, of course, on the nature of the Substance of member .14. If plasterboard or plaster are the materials of construction of member 14, the prongs 2S are inserted by light hammer blows. On the other hand if member 14 is concrete, either the prongs 28 may bev omitted or the entire face plate 24 omitted.

There are two tubular expansion members .or cones -30 and 32 in the bore 36 delined by the spirally wound group of wires. Cone 32 is rheld captive in the bore by means of wall 2-0, and it has a smooth outer surface 38 and an internally threaded bore 40 along the central axis thereof.,

The embodiment of FIGURE 7 differs from the modication of FIGURE 4 by having cone 32a made sectional to facilitate spreading of the wires y16. Cone 30 has a smooth bore or passage 44 coaxial with bore 36 and threaded bore 40. The outer surface 48 has serrations 50 thereon to enhance the gripping action between the outer surface and the side wall of bore 36. The serrations 50 may assume a number of configurations, one of which is shown in FIGURES 2 and 3 and consists of a coarse screw `thread. Although cone 32. is held captive in bore 35, .cone 30 is merely set into bore 36 (FIGURES 1 and 2) and is adapted to be t-apped into the bore by light hammer blows to cause a spreading of one end of the anchor. The spreading of the opposite end of the anchor is achieved by propulsion of the cone 32 inwardly of the anchor.

A bolt or screw 54 constitutes a part fof the anchor. It is threaded into the threaded bore 40, after passing through the smooth bore 44 and passing comparatively freely through the intermediate part of bore 36. Opening 22 is to allow the innermost end of the screw or bolt to pass therethrough.

Installation of the anchor 10 is accomplished in this way: it is assumed that aperture 12 is drilled or otherwise formed in member 14. The anchor is inserted in the opening 12, and the face plate, when used, is also anchored to member 12 by tapping the face plate in a direction to insert prongs 28 into member 14 (FIGURE 2). Then spreader 30 is tapped inwardly of bore 36 by hammer blows of sutlicient force. When the larger diameter end of the spreader 30 is flush with the outer surface of face plate 24, one end of the spreader will have expanded (FIGURE 3) spreading the strands or wires of group 16, and the resilient cover 18.

Then the screw 54 is inserted and threaded through the threaded bore 40 of spreader 32. By tightening the screw (FIGURE 5) the spreaders 30 and 32 will be drawn acores@ deeper into bore 36, causing a further spreading action at the opposite end of the anchor. Consequently, the anchor, when installed, is spread at both ends as shown in FIG- URE 5, and the screw 54 may be removed with the anchor tirmly heid in place. After removal of the screw, any article to be fastened in place may be applied and the screw returned with the threads of the screw engaging threaded bore 40.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In an expansible anchor, the combination of a substantially tubular core comprising a set of spirally wound Wires, a tubular jacket of resilient material enclosing said core, a pair of frusto-conical expanding members positioned in the respective end portions of the core and provided with axial bores, the bore of one of said expanding members being screw-threaded, an expanding screw rotatably extending through the bore of the other expanding member and through the intermediate portion of the core and threadedly engaging the member with the threaded bore, whereby when said screw is tightened said expanding members may be drawn together to radially expand the end portions of said core and the end portions of said jacket enclosing the same, an end plate disposed at one end of said core and projecting radially outwardly beyond the outer surface of said sleeve, one of the Wires of said core being secured to said end plate, the other Wires of the core being detached from the end plate, and anchor means on the end plate for preventing rotation thereof when said screw is tightened.

2. An expansible anchor for mounting in an opening in a support, said anchor comprising a tubular core open at its ends and including a plurality of spirally wound resilient metallic Wires, a tubular jacket of resilient material and open at its ends enclosing the core, an end plate on the core amxed to one of the wires and free of the other wires, said end plate abutting one end of the core and the jacket, ltubular conical expansion members in the end portions of the core, one of said expansion members being segmental and internally threaded, the other of said expansion members being externally threaded and having a smooth bore, a retaining cap on the other end of the jacket for said one expansion member, said end plate having an opening therein aligned with the core for the insertion of said other expansion member, and a bolt rotatably mounted in said other expansion member and threaded through said one expansion member for drawing the members toward each other for expanding the core and the jacket.

3. An expansible anchor in accordance with claim 2, said retaining cap having an opening therein aligned with the expansion members and the core and receiving said bolt.

4. An expansion anchor in accordance with claim 3, said end plate being engageable with a support for anchoring the core in an opening therein, said end plate comprising a plurality of prongs struck therefrom and adapted to be driven into the support.

References Cited in the file of this patent UNITED STATES PATENTS 1,120,409 Rohmer et al Dec. 8, 1914 1,307,418 Raeger June 24, 1919 2,326,453 Gelpcke Aug. 10, 1943 2,553,614 Valluzzi May 22, 1951 2,559,281 Croessant July 3, 1951 FOREIGN PATENTS 403,113 Great Britain Dec. 14, 1933 544,885 Great Britain May 1, 1942 577,218 Italy Mar. 27, 1958 

1. IN AN EXPANSIBLE ANCHOR, THE COMBINATION OF A SUBSTANTIALLY TUBULAR CORE COMPRISING A SET OF SPIRALLY WOUND WIRES, A TUBULAR JACKET OF RESILIENT MATERIAL ENCLOSING SAID CORE, A PAIR OF FRUSTO-CONICAL EXPANDING MEMBERS POSITIONED IN THE RESPECTIVE END PORTIONS OF THE CORE AND PROVIDED WITH AXIAL BORES, THE BORE OF ONE OF SAID EXPANDING MEMBERS BEING SCREW-THREADED, AN EXPANDING SCREW ROTATABLY EXTENDING THROUGH THE BORE OF THE OTHER EXPANDING MEMBER AND THROUGH THE INTERMEDIATE PORTION OF THE CORE AND THREADEDLY ENGAGING THE MEMBER WITH THE THREADED BORE, WHEREBY WHEN SAID SCREW IS TIGHTENED SAID EXPANDING MEMBERS MAY BE DRAWN TOGETHER TO RADIALLY EXPAND THE END PORTIONS OF SAID CORE AND THE END PORTIONS OF SAID JACKET ENCLOSING THE SAME, AN END PLATE DISPOSED AT ONE END OF SAID CORE AND PROJECTING RADIALLY OUTWARDLY BEYOND THE OUTER SURFACE OF SAID SLEEVE, ONE OF THE WIRES OF SAID CORE BEING SECURED TO SAID END PLATE, THE OTHER WIRES OF THE CORE BEING DETACHED FROM THE END PLATE, AND ANCHOR MEANS ON THE END PLATE FOR PREVENTING ROTATION THEREOF WHEN SAID SCREW IS TIGHTENED. 